Opinions run strong among hunters on the issue of shotgun hunting for deer.
Some view it as wasteful and inhumane for the animal,
since shotguns lose accuracy and power beyond 100 yards, leading to wounded and unrecovered deer.
Some view it as an infringement of their civil rights,
weapon restrictions being the thin wedge that later becomes an outright ban on all hunting or shooting.
Others view it as a safety measure essential for areas with sufficient population density.
Shotgun projectiles - whether buckshot or slugs - don't carry energy as far as a rifle bullet.
Reducing the chance of a stray projectile causing unintended property damage or bodily injury improves hunting safety,
which means it can actually help to protect hunting from those who would otherwise find excuses to ban it outright.
I believe all of the above have some truth.
Yet the first argument needs to be qualified.
While it's true beyond 100 yards, the exact opposite is true at close range.
In my experience, at close range nothing kills a deer quicker, more reliably and more humanely than a 12 gauge.
Ballistically, rifles may have more energy and momentum but a 12 gauge actually delivers more energy and momentum to the animal.
With a well placed shot the deer is often dead before it hits the ground.
Constrast that with a deer being hit with a .308 or .30-06,
where even a well placed shot is rarely an instant kill.
The deer usually bolts and runs for several seconds before falling.
Where I live there are neighbors several hundred yards away through the forest.
There is no way I would be firing a high powered rifle at anything unless it were a dire self defense situation
(which is virtually impossible since there are no large carnivores around here).
But a well placed shotgun blast of 00 buck, especially after passing through a deer,
is virtually guaranteed not to travel through the forest and strike anything unintended.
So shotgun deer hunting offers two key benefits.
But it also has its drawbacks.
Here I will share what I've learned - some the hard way.
Most shotguns are made for shooting clay pigeons and game birds.
Shooting at stationary land based targets, the POI of such a shotgun is usually several inches high.
The shotgun hunting neophyte will typically put the bead right on the deer's front shoulder
and send the slug or buckshot flying harmlessly right over the deer's back.
I find it necessary to put the POA on the deer's front knee (at close range),
or at the base of the torso above the front knee (at longer range).
This puts the POI right at the vitals: at the front shoulder, almost midway up the torso.
That makes the POI 6" to 12" higher than the POA.
This is with my 870 Express 12 gauge, 26" barrel and IC choke, using 3" magnum 00 buck or a 2 3/4" slug.
That may sound excessive, but with trap or game birds this shotgun does not shoot high - it's dead on the bead.
Make sure to aim properly.
The single front bead on most sporting shotguns can be used with accuracy, but it takes practice.
You may shoot half dollar coins at 100 yards with your .308 but that doesn't mean you can hit a deer at 50 yards with a shotgun.
It's a whole different ball game that takes its own practice.
Make sure to use the right ammunition.
You need good penetration at distance.
I prefer the confidence of using 3" magnum 00 buck.
They are generally unnecessary for personal defense,
which is typically close range against human or dog attackers.
But hunting deer presents an entirely different set of requirements.
Consider that each pellet in 12 gauge 00 buck is 33 caliber, 54 grains traveling about 1300 fps at the barrel.
This is comparable to a single bullet from a .22 long rifle - hardly enough to reliably stop any large animal.
A standard 2 3/4" shell has 9 of these pellets - so now we're getting somewhere in stopping power.
But consider that at 50 yards those pellets have slowed down to about 1100 fps.
That's about 85% of its original velocity,
which doesn't sound bad until one recalls that energy is proportional to velocity squared,
so it's only 72% of its original energy.
In contrast, a 3" shell has 15 pellets and leaves the barrel a bit faster: 1350 to 1400 fps.
That's 67% more mass which makes 67% more hitting power and energy from the pellets alone.
Now add 7% more speed which means 16% more energy and you have 183% which is nearly TWICE the energy and hitting power.
At point blank range the standard 2 3/4" shell would do the job.
But we don't typically shoot deer at point blank range, and the 2 3/4" loses energy quickly.
The 3" magnum gives you superior downrange performance which is where you need it most.
As for recoil, some say the 3" abuses the shoulder
but I can't recall ever noticing the recoil when hunting, even with a 3" magnum load.
The adrenalin and excitement of the hunt simply obviates it.
Make sure to have the right followup shot.
I always put a 2 3/4" 1 oz. slug next in the tube.
Unlike what Hollywood movies would have us believe, it is indeed possible to miss with a shotgun.
Not only does the shot go high against land based targets,
the pattern doesn't spread as quickly as most people think.
It's also even more common to get a glancing blow - especially beyond 50 yards on a moving deer.
The first shot might take the deer down, but be prepared if it gets back up again.
1 oz = 28 grams = 432 grains, at 1500 fps is about 2,150 ft.lbs. of energy.
This is less energy than the roughly 3,300 ft.lbs. of a 3" mag 00 buck,
but it is concentrated into a single slug so it has far greater penetration.
One shot to the vital area will instantly kill any deer or large animal.
I've had a slug blow the opposite side front leg clean off the deer.
Even though a .308 or .30-06 has more energy, it doesn't transfer as much of its energy to the animal -
even a soft nose hunting bullet is so much smaller (30 versus 74 caliber) it tends to poke a hole and keep going.
The slug has high energy transfer which is good in 2 ways:
First, devastating stopping power. Second, the projectile having transferred its energy to the animal,
poses less of a threat to people, buildings or anything else downrange.
Overall I would not say that the 12 gauge is "better" or "worse" than a .308 or .30-06 for deer hunting.
They are different tools for different situations.
For hunting in the remote outdoors where people & property are not an issue and deer are typically far away,
the rifle is definitely the superior precision tool.
But for rural areas where people & property may be nearby and the deer are usually at close quarters,
the shotgun provides unmatched stopping power with a margin of safety.